- History of myocardial infarction, unstable angina, congestive heart failure New York Heart Association class III/IV, cerebrovascular accident, transient ischaemic attack, limb claudication at rest in the previous 6 months, or ongoing symptomatic dysrhythmias, or uncontrolled atrial, or ventricular arrhythmias, or uncontrolled hypertension defined as systolic blood pressure ≥150 mmHg or diastolic blood pressure ≥90 mmHg